Typically, when transferring fluids from a container, it is necessary either to attach a pouring spout to the container or to insert a funnel into the receiving vessel to prevent unwanted spillage. Such transfer methods are commonly used to deliver fluids such as motor oil, antifreeze, transmission fluid, and gasoline additives to an automobile. A common problem when using transfer devices such as a pouring spout or a funnel to transfer such fluids is that they frequently become contaminated, particularly if they are used with some sticky substance such as oil, coolant, and the like. As a result, a user must locate, clean, and dry the transfer device prior to each use to avoid contamination of the fluid during transfer to the receiving vessel. The user must also select a transfer device of an appropriate size and shape to enable the transfer of fluids without spillage. However, many of the known transfer devices are not adapted to fit closely to the mouth of the container from which the fluid is poured, thus spills are frequent when either the spout or container is inadvertently moved, resulting in an inconvenience to the user for having to clean up the spill or a detrimental environmental impact in the case of oils and coolants leaking into the ground. Nor do many of the known transfer devices enable closed fluid transfer in which the fluid is transferred from the container to a receiving vessel or area without being exposed to the environment.
It therefore would be desirable to provide detachable dispensing systems for containers that are capable of ameliorating some or all of the foregoing disadvantages. In particular, it would be desirable to provide detachable dispensing systems that facilitate efficient, clean, and protected transfer of pourable materials from a container.